The present disclosure relates to a semiconductor device, and more particularly, to a fuse part of a semiconductor device, and a method of fabricating the same.
When a semiconductor device is highly integrated, the semiconductor device includes a number of minute memory cells. Thus, there is a possibility that a defect occurs in a portion of the memory cells during the fabrication of the semiconductor device. Even when the defect occurs in only one of the memory cells, the corresponding semiconductor device is discarded as an inferior product.
In other words, even though a defect may occur in only a few memory cells out of the whole of a much larger number of memory cells in a semiconductor device, the entire semiconductor device is discarded to reduce a production yield.
Accordingly, a redundancy cell for replacing a defective cell is provided in a some semiconductor devices. Generally, the redundancy cell includes a spare row and a spare column in a particular cell array.
A process for replacing a defective cell will now be described in detail. The defective cell is selected through an electrical die sorting (EDS) of a semiconductor device in which a wafer processing is completed.
A corresponding fuse within a fuse box provided in a peripheral circuit region of the semiconductor device is cut by applying a laser beam irradiation. That is, a blowing pad of the corresponding fuse is laser-irradiated to burn an interconnection. In this manner, the defective cell is replaced with the redundancy cell. In situations where an address of the defective cell is inputted, the redundancy cell is accessed instead of the defective cell.
The process of replacing the defective cell with the redundancy cell is referred to as a laser repair process. Although the defect occurs in the portion of the memory cells, there is no need to stop using the semiconductor device. Therefore, the production yield of the semiconductor device can be improved.
FIG. 1 illustrates a fuse part of a related semiconductor device.
Referring to FIG. 1, a plurality of line type fuses 102 extending in the same direction are disposed over a fuse part 100. Each of fuses 102 includes one blowing pad 102A for irradiating a laser beam.
A laser repair process can be performed one time at each fuse. Even when the laser repair process fails in only one cell because an interconnection is not completely burned, or a residue of the fuse remains over a substrate, the corresponding semiconductor device must be discarded.
When thicknesses of a remaining oxide (ROX) layer remaining over the blowing pad 102A are different in accordance with wafer regions and lots due to a process parameter, the probability of failure of the laser repair process greatly increases. This in turn significantly reduces the yield of a semiconductor device fabricating process.